The new cultivar, Aeonium ‘Black Diamond’, was found by the inventor, Renee O'Connell, as the result of a crossing made May 2013 as part of a planned breeding program. The seed parent variety is the unpatented proprietary variety referred to as Aeonium hybrida ‘Dark 11’. The pollen parent is the unpatented variety Aeonium hybrida ‘Zwartkin’. Aeonium ‘Black Diamond’ was selected by the inventor, Renee O Connell, in September of 2014 from a group of seedlings resulting from the 2013 crossing, at a commercial greenhouse in Vista. Calif.
Asexual reproduction of the new cultivar ‘Black Diamond’ was first performed in Vista, Calif., at a commercial greenhouse, by vegetative cuttings in October of 2014. ‘Black Diamond’ has since produced multiple generations and has shown that the unique features of this cultivar are stable and reproduced true to type.